The present invention relates to an apparatus and a method for automatically feeding a sewing machine with a sock tip.
As known, socks manufactured on circular machines for socks are currently defined by a tube having a heel and a tip which, once the tube has been completed, remains open. Thus, after manufacturing the sock, the latter is manually taken and, after orienting the two sides of its aperture in a predetermined way, it is inserted into a suitable sewing machine which sews the tip closed, thus connecting the two edges of its aperture.
In some types of circular machines for socks, the sock tip has recently been directly sewn in the machine for manufacturing it. However, beside being extremely complex and expensive, and beside significantly complicating the entire structure of the machine, such a solution has the disadvantage of frequently jamming the machine, which interrupts not only the sock tip sewing, but also the production of the sock.
In fact, in a particular type of circular knitting machine for manufacturing socks, each sock is arranged so that its tip is sewn, and it is withdrawn by means of the cylinder needles to the needles of the withdrawing device, with all the consequences that such operation implies.
In another type of machine the tips are even sewn together in the same machine that manufactures the socks, thus further complicating same and further increasing the possibility of jamming the machine. Moreover, sewing of a sock tip together in the machine that manufactures it implies that a separate device adapted to sew the sock tip must be arranged on each machine. Thus this device can be only applied to that type of machine and not to other types of machines.
For these reasons, and for the considerable purchase costs of the machines used for such purpose, sock sewing is still substantially carried out by manually withdrawing the sock from the machine and then orienting it in a suitable way on the sewing machine, with a consequent use of manpower which makes the production and sales costs of the finished sock increase.
The object of the present invention is to eliminate the disadvantages of the prior art mentioned above.
Within the scope of this object, and important object of the present invention is providing an apparatus and a method for automatically feeding a sewing machine with a sock tip which should allow this operation to be done outside the machine that manufactures the sock so as to be an autonomous and independent operation with respect to the actual manufacture of the sock tube.
Another object of the invention is providing an apparatus and a method for automatically feeding a sewing machine with a sock tip which could be applied to any machine for manufacturing socks without having to substantially modify its structure.
Another object of the invention is providing an apparatus and a method for automatically feeding a sewing machine with a sock tip which allows concurrently feeding a sewing machine from one or more machines that manufacture the socks.
A further object of the invention is providing an apparatus and a method for automatically feeding a sewing machine with a sock tip wherein the apparatus is not part of the circular sock machine, thus preventing a considerable complication of same and preventing the possibility of jamming it.
A further object of the invention is providing an apparatus and a method for automatically feeding a sewing machine with a sock tip wherein the sock withdrawal from the needle cylinder occurs without having to deliver the stitches by the cylinder needles to the withdrawing device so as to eliminate any difficulty which the operation implies.
Last but not least, another object of the invention is that of providing an apparatus and a method for automatically feeding a sewing machine with a sock tip which allows reducing or totally eliminating the use of manpower with consequent relevant having on the production and sales cost of the finished product.
These objects are achieved by an apparatus for automatically feeding a sock tip to a sewing machine, the apparatus comprising a device for gripping the sock from the area of formation of same on a circular machine for socks and at least one device for transferring the gripping device in a final predetermined position for feeding the sewing machine. According to the invention rotation means for the gripping device imparts a rotation speed to it that is synchronized with the rotation speed of the needle cylinder of the circular machine when the gripping device is in a predetermined position inside the needle cylinder so as to form an annular gap with the latter, inside which the sock hangs during its formation.
Another object of the present invention is a method for automatically feeding a sewing machine with a sock tip which is characterized in that it consists in moving a gripping device of the sock into the needle cylinder of a circular machine for socks by concurrently applying air suction inside it, in bringing the gripping device into rotation in synchrony with the needle cylinder, in manufacturing the tube of the sock without a knit course, in pinching the knit of the tube by the gripping device on at least two diametrically opposed portions, in completing the knit course of the tube in the needle cylinder so that, once completed, the sock is oriented according to a predetermined orientation according to the final requirements, and in withdrawing the sock thus oriented from the needle cylinder to move it to the sewing machine.
Again, the sock obtained through the method described above and with the equipment described above is characterized in that, near the sewing portion of the aperture of the sock, it comprises a thickening adapted to define a mechanical abutment for aligning the sewing portion with the guides of the sewing machine.